Such a damper or insulator is known from DE 198 55 708 B4. This damper has proved itself in practice but is not sufficiently wide-band. Hereinafter, a damper is considered to be wide-band which has a damping effect above a threshold value, for example above 20 dB, between a lower frequency fu and an upper frequency fo, and in which the upper frequency fo is at least three times the lower frequency fu, in particular at least four times, preferably five times. This damping effect is supposed to be provided under operating conditions.
Internal combustion engines with turbochargers, particularly injection engines with turbochargers, are increasingly used in automobile engineering. This leads to engines with an ever smaller cubic capacity and thus, ever smaller dimensions. Thus, the construction spaces also become smaller and the space available for sound insulation becomes increasingly smaller.
The operating noises emitted by the engine are to comply with predefined requirements and conceptions; a good sound of the engine is desired. In the case of turbocharged engines, noises occur due the splitting of charge air within the turbocharger with further noises added to that. In particular, noises that lie within the human auditory range are supposed to be dampened as much as possible; a desired noise emission is to be accomplished. In this case, the engine developers increasingly demand sound reductions over wide frequency ranges, for example in the range of from 2000 to 10000 Hz, with the smallest of construction spaces being provided.
The known damper is configured as a tubular chamber damper which comprises two slit chambers axially disposed one behind the other. With it, the required minimum damping effect can be achieved only in a smaller frequency range.
Thus, a damping effect in a sufficiently wide frequency range with as small a design as possible is desired. The damper is supposed to be inexpensive to manufacture and is supposed to be capable of being assembled from components that are easy to produce and mount. Metal and/or suitable plastics are possible materials. A working temperature of 180° C. and above and a pressure of usually 1.8 bar in the damper are to be taken into account.